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Chapter 6 Broadband
EX5501-B0 / AX7501-B0 / PX7501-B0 User’s Guide
94
• Leading zeros in a block can be omitted. So
2001:0db8:1a2b:0015:0000:0000:1a2f:0000
can be
written as
2001:db8:1a2b:15:0:0:1a2f:0
.
• Any number of consecutive blocks of zeros can be replaced by a double colon. A double colon can
only appear once in an IPv6 address. So
2001:0db8:0000:0000:1a2f:0000:0000:0015
can be
written as
2001:0db8::1a2f:0000:0000:0015
,
2001:0db8:0000:0000:1a2f::0015
,
2001:db8::1a2f:0:0:15
or
2001:db8:0:0:1a2f::15
.
IPv6 Prefix and Prefix Length
Similar to an IPv4 subnet mask, IPv6 uses an address prefix to represent the network address. An IPv6
prefix length specifies how many most significant bits (start from the left) in the address compose the
network address. The prefix length is written as “/x” where x is a number. For example,
2001:db8:1a2b:15::1a2f:0/32
means that the first 32 bits (
2001:db8
) is the subnet prefix.